Complex conditions with OR blocks?

Use "System evaluate expression" or "Pick by evaluate" if you need to pick instances.

In the expression you can use boolean operators & and |, for example:

(a & b) | (c & d)

And even ternary operator:

a ? "result1" : ((b | c) ? "result2" : "result3")

Of course this won't work with specific conditions like "object is overlapping" or "object is visible". You will need to break the logic into several events in this case.