Understanding Taproot Expressions and Miniscript

I’m trying to figure out how to describe a Script Tree with both Script Path 1 and Script Path 2 using Taproot expression. So, I have this tr(InternalKey,{multi_a(2,Key1,Key2),pk(Key3)}) to import into Bitcoin core. But if I want to tweak script path 2, like changing it to something else, what goes in there? tr(InternalKey,{sortedmulti_a(2,Key1,Key2),???)

Descriptors cannot describe all arbitrary scripts, only a subset with specific properties that make them analyzable. You must use Miniscript for those scripts. The miniscript that you want is probably something like and that would make a script of

Thank you for the explanation. Now I know that because tree expressions in Taproot output have limitations, then to describe certain arbitrary scripts I have to use Miniscript, so that valid descriptors can be generated. With your explanation, I succeeded in importing the descriptor: tr(InternalKey,{sortedmulti_a(2,Key1,Key2),and_v(v:pk(key3),older(10))}) , and successfully created a transaction with the multisig 2-of-2 script path spend (through the GUI or using a console with walletcreatefundedpsbt option), but still have no luck in creating transactions with and_v(v:pk(key3),older(10)) script path spend.

Not all Miniscript can be signed yet. I think we haven't implemented everything that's needed to pass in the information required to sign for both kinds of timelocks as well as hashlocks.

Ah, I see. I thought there is something wrong with the variables that I used when building the transaction with walletcreatefundedpsbt, because for every change in the variables and arguments that I used, the results are the same, where the psbt cannot be signed with (Key3) descriptor.