Currently it is not possible to do that. The only way to do that is to manually add the same product several times and remove the variants you don't want to display, so it can be time-consuming if you have a lot of variants.

To be able to select the variant you must go to the product editor and change the main image for the variant that you are going to leave in that box, also click on the eye to avoid showing another variant

Then in product information, you must modify the information of each product that you are going to show in the catalog. Then you will save the changes. The changes will only be reflected in the catalog, not on your main product page.

You must do this process with each product, so if there are several variants, the work requires a lot of time.