Assuming you are using tiddlywiki 5, the easiest way is probably using a button and action-navigate like this (using
tiddlywiki.com as an example because that is where I tested it):
<$button class='tc-btn-invisible tc-tiddlylink'>Test
<$action-navigate $to=HelloThere $scroll=no/>
<$action-navigate $to=About $scroll=no/>
</$button>
Just change HelloThere and About to whatever tiddlers you want, and add more action-navigate widgets as needed. The tc-btn-invisible and tc-tiddlylink classes make it look like a normal link to a tiddler. If you do want the wiki to scroll to the newly opened tiddlers just remove the $scroll=no part.