approve its tokens for another address?
This isn't very clear. "Its" could mean tokens the contract wants to spend or tokens the contract wants to receive.
@Laurie is exactly right if it's the former case. The contract can spend its own money just like anyone include authorizing another contract to
If you want the latter case, e.g. The contract wants to "approve" the transfer of Alice's tokens to itself, then no, this is not the intended behaviour. Having said that, anyone can implement a token with novel rules but such a "feature" would be controversial and probably not acceptable to most token holders.
Hope it helps.