That looks like the top part of a cymbal stand, not a proper stacker. If both male threads are the same (M6 probably) this might work:

https://www.amazon.com/Coupling-Straight-Fitting-Threaded-Studding/dp/B07Q2PSTK4/ref=sr_1_3?crid=2G5SICHGCMV41&keywords=m6%2Blong%2Bthreaded%2Bnut&qid=1686939280&s=industrial&sprefix=m6%2Blong%2Bthreaded%2Bnut%2Cindustrial%2C103&sr=1-3&th=1