Let's say you're using a multiple select formmenu, and you've given it a name setting to be able to re-use its contents elsewhere in your snippet.
If you simply re-use the name, the output will be presented in a "list form", which doesn't exactly look great. See below:
{formmenu: multiple=yes; name=mymenu; choice1; default=choice2; default=choice3}
{=mymenu} <- This looks meh...
However, you can use the "join" function to join the items with a specific character or string, and present them as you please.
{formmenu: multiple=yes; name=mymenu; choice1; default=choice2; default=choice3}
Joined by a new line ("\n"):
{=join(mymenu, "\n")}
Joined by a comma (", "):
{=join(mymenu, ", ")}
Joined by a tab space ("\t"):
{=join(mymenu, "\t")}
Play around with the join function and see what ideas you can come up with. You can read more here: https://blaze.today/formulas/reference/
And of course, if you have any questions, feel free to ask in this thread and I'll be happy to help!