Not saying this is a way to do it, but just offering this story because I remembered it and found it interesting:
There's someone who used to post online who claims to have success breeding bettas with a two-tank setup and a water bridge between them. He says that the two tanks give the fish ways to escape from each other and also come together for breeding when desired. I think he had several females in one tank and a single male in the other, but they used the bridge to find one another for mating
I can't find the site I saw before, but here is a video on youtube of a similar setup, but using two males. I wouldn't do it with two males myself, and I think the tanks in this video are way too small, but you can see the bridge concept anyway. I could see a disaster if a male and a female met on the bridge and tried to mate there, but he claimed they just used it for going back and forth.
Someone else posted once that he spent a lot of time and effort making a bridge, and his crayfish immediately took up residence there and wouldn't let anyone else pass by.