Hiding a field or table

I'm new to Ninox.  I have some individual fields and some sub tables that display my old imported data.  I want these visible until the user fills out info in the newly created sub table, then the old table is to be hidden.

I thought the formula might be- display field only if there is an entry in the new table greater than 1?

But I don't know how to write this formula correctly.  I've managed to hide other fields, but not when working with info in sub tables.