With how it currently works you’d have to use expressions, for example:
0x000c0238 input_state 0 lt
1 recall not
1 recall
ifte
1 store
0x000c0238 input_state 0 gt
2 recall not
2 recall
ifte
2 store
and map Register 1 to Layer 1 and Register 2 to Layer 2:
This will toggle them independently, meaning both layers can be active at the same time and activating one does not deactivate the other, which might not be what you want.