Share in property has been given to A and B as per will along with 3 other beneficiaries 

person making the Will is giving their share of the Joint Family Properties to A and B, along with X, Y and Z, and they will have exclusive ownership of the properties.

This means the testator i.e., the person who has written  this Will has distributed his undivided share out of the joint family property jointly to A & B along with X, y and Z.

Thus the said beneficiaries shall acquire the undivided share of the testator after his lifetime by enforcing this Will jointly and can enjoy them jointly. 

- It means the testator (The person who is writing the Will) , is transferring his undivided joint family properties in favour of A and B along with XY and Z jointly. 

- Hence, after the demise of the testator , A & B and XYZ jointly will right over the property left by him without any obstruction. 

Undivided share in property is bequeathed to A & B jointly and exclusively and also to X,Y & Z. There is ambiguity. If share is bequeathed to A & B jointly and exclusively, it cannot be again bequeathed to X,Y & Z. Interpreted in plain language, X, Y & Z are not entitled to claim any benefit out of will. 

It will be divided in 5 shares to 5 people 

going by the plain and simple meaning of the clause it appears that what the testator meant was that he wishes to bequeath his undivided share in the joint family property jointly to X,Y,Z, A and B

It is not specified in the query whether X,Y,Z,A and B are in anyway related to the testator

also it remains to be ascertained whether the testator meant that this undivided share should go to the above persons as 'joint tenants' or as 'tenants-in-common'

in case of joint tenants, x,y,z, a and b would be entitled to jointly hold the UDS of testator. so if x dies, the others i.e. y,z,,a and b will continue to hold as joint tenants

however in case of tenants in common, if say, x dies, then the x's share will devolve on his legal heirs and will not go to the survivor tenants in common , ie to y,z,a and b

the aforesaid can be ascertained upon reading the entire Will in its proper context 

a)  The Will is very clear about bequeathing the undivided share pertaining to the testator for acquisition by the beneficiaries therein.

b) From your contents it can be seen that A & B are entitled to a share equally along with the other beneficiaries namely X, Y & Z.

c)  No comments

a. it appears that there was a division/partition in the lifetime of the testator, between himself, his father and his brothers

so whatever share the testator got upon such partition, would be his self acquired property, since upon partition, the property loses its character of a HUF property

i assume that the succession in this case opened after the coming into force of the Hindu Succession Act, 1956. that is, the testator died after 1956

the HSA 1956 codified the old Hindu law pertaining to joint family properties

your query does not have the full details since the date of death of the testator is important to know exactly when the succession opened

since there is a testamentary disposition in this matter [which is permitted i guess u/s 30 of HSA], S.6 of HSA which pertains to devolution of interest of a coparcenor in a HUF property, will not apply 

one thing is certain that since there was a prior partition, the share which the testator got on that partition was his self acquired property and cannot be called HUF property unless the testator threw that share into the common hotchpotch of an already existing HUF between himself and his children [after 2006 even daughters are considered as coparcenors]

the wife of a coparcenor is not considered to be a coparcenor. she only gets a share equal to that of the son, upon a partition 

so if i assume that there is a HUF property, then the testator would be having 1/5th UDS [wife is not counted]

so as per his Will he has bequeathed his 1/5 UDS to 5 people i.e. his widow and 4 children

so as per the Will the widow will be entitled to 4%

each child being a coparcenor was already holding 20% share (1/5). they get 4% share from the testator's 20%

so their share increases to 24% each

so 24% x 4 children + 4% of widow = 100

the aforesaid would be the devolution of the UDS of the testator as per his Will

b. A,B,X,Y and Z get equal share from the UDS 20% of the testator

c. testator can bequeath his UDS in the ancestral property to any person of his choice. He may, say, exclude X,Y and Z. However from your first query, it does not appear so, since the words used by the testator are 'alongwith X,Y and Z

Sir, it is simple common sense. No 2 lawyers will have the same opinion. Just as 2 doctors wont. So please dont expect all lawyers to give you a common answer. To enlighten you, all the answering lawyers here answer independently of each other on an 'honorary basis' and there is no consultation among them before shooting their respective replies  

"undivided share' referred herein means the share that testator received in the division amongst his father, 
himself and his brothers 

2) he cannot deprive X, Y , z of the ancestral share 

3) A and B get one fifth share 

Its the latter.

It's equal as the will is not clear 

No they can't be deprived 

Dear client   The line means that the person making the Will is bequeathing their undivided share in certain joint family properties to A and B jointly and absolutely. The phrase "undivided share" means that the person owns a part of the property as a co-owner along with others, and that share is being bequeathed. The phrase "in favor of" means that the ownership of the undivided share is being transferred to A and B. The phrase "jointly absolutely and exclusively" means that A and B will hold the undivided share together, and that their ownership will be exclusive of other persons, including X, Y, and Z. The mention of X, Y, and Z in the clause could mean that they are the co-owners of the joint family properties, but their shares are not being bequeathed in this Will.