How can I transfer a "Query-Builder-Diagram" from one database to another?
Hence, from production to development?
Assuming that the same tables/views/schemas that are referenced in your query exist in both databases, and those objects have the same attributes, then you can save the Visual Query as a "Toad SQL Model file" (.tsm format) by right-clicking on the Query Builder doc tab and choosing Save File, per snap below.
When you're ready to run the query again (say, on that second Prod database), you can connect TDP to your database # 2, and open the Query Builder file you previously saved. TDP will open the original connection that the query builder was created for, but you can right-click on the Query Builder doc tab and Change Connection to your Prod database.
Hope this helps you farther along.