Can an account define conditional tags to blockchain Let me try to specify my question with an example:

Consider that there are 4 accounts ( AccountA and AccountB and AccountC (Taged as Store) and and AccountD (Taged as Night Club)), and AccountA wants to send let's say $100 to AccountB with a specified condition (i.e. $100 can be spent only at Accounts taged as Store ).

Can i implement above case?

If i can, how?
Not directly.  The Bitcoin protocol doesn't allow you to place restrictions on how a transaction can be spent.  The input script doesn't get to see the output script.

However, the net effect of what you describe would be as follows: after B decides to send the funds, they are in the control of C, who can spend them as desired.  In other words, the approval of both B and C is needed in order to move the funds onward.  You can get this effect with a 2-of-2 multisig transaction that requires signatures from both B and C, and can then be spent in any way they agree to.