Does bitcoin have this? Obviously the math would differ in bitcoin possibly, i'm speaking only in the functionality. I would think this would be a good addition to multisignature...the idea of one key having more 'importance/relevance' than another with differing numbers of keys required based on their 'level'.
There isn't a single opcode to do it.
If you wanted one master key and 2 of 3 of the other keys, you could use the following scriptPubKey
OP_CHECKSIGVERIFY OP_2 OP_3 OP_CHECK OP_CHECKMULTISIG
To spend it, you use the following scriptSig
OP_0
The OP_CHECKSIGVERIFY checks the master sig and then the OP_CHECKMULTISIG checks the 2 out of 3 for the sub-signatures.
You can use OP_IF / OP_ELSE to have multiple options.
OP_IF OP_CHECKSIG OP_ELSE OP_2 OP_2 OP_CHECKMULTISIG OP_ENDIF
This means either you sign using the private key associated with pub-keyA or you can sign with the private key associated with (2 of 2) pub-keyB1 and pub-keyB2.