This is not possible. The reason is that this is a very fragile way to create cross-references, kind of replicating the issues everyone is facing with cross-references in the traditional MS Word world. Allow me to explain.
In order to reach optimal reusability of clauses, ClauseBase nudges you to treat clauses as interchangeable black boxes.
This may sound abstract and theoretical, but is actually critical to allow clauses (or even entire annexes / schedules) to be easily interchanged. After all, if every clause in the contract would have to be concerned about the inner structure of all other clauses, then interchangeability would become very difficult.
Just a few carefully chosen things are therefore available on the “outside” of the black box (e.g., a cross-reference or an implements-link or defines-link); all other things on the “inside” of a clause can effectively be ignored by other clauses.
What you now want to do with your internal cross-references, would break this idea, as you would effectively require your first clause to have “knowledge” of the inner structure of the target clause you are referring to with the cross-tag. This is all fine in a small document in the short term – and so I fully understand the temptation to do so – but tends to become very dangerous over time, as you do not know today whether you (or some colleague) in the future will happen to use another clause for that target cross-tag. Or will happen to change the structure of the target clause, effectively removing the target paragraph, or submitting it to some condition that may suddenly no longer be fulfilled. Or perhaps your current clause is so incredibly well-written that it will end up in a completely different contract, with a completely different context, and with completely different clauses labelled with the target cross-tag.
These kinds of issues are exactly the reason why the “Error! Reference source not found!” is so prevalent in the traditional MS Word world.