Exclude from certain indexes (not all)

Is it currently (or could it be made) possible to exclude a node from specific indexes, rather than all of them?

I have a number of indexes, some of which contain the same bundle, but for which I want users to have the ability to exclude specific nodes from specific indexes.

For example:

Index 1 contains Bundle A and Bundle B
Index 2 contains Bundle A and Bundle C

I want Node 1 (exists in bundle A) to be indexed in Index 1 but not in Index 2.