In leanIX you can create new Fact Sheets while editing a Fact Sheet Section.
If you don't see a Fact Sheet you want the visited Fact Sheet to be linked to while editing a section, you easily type in the name of the new Fact Sheet you want to have linked here and click "NEW". Now the new Fact Sheet will be created, the link is set between both the Fact Sheets automatically and you easily can fill the needed data in the new Fact Sheet.
This is "On-the-Fly" (E.G. to create a Predecessor-Application in a Fact Sheet):
You can manage the settings for "On-The-Fly" in case of creating new Fact Sheets in "Customize Fact Sheet" (Admin Only) in the setting "On-the-fly creation". More info for this function you find here.
This way you also can set Tags "On-The-Fly"
But attention with Tags created this way! They are not automatically associated to a Tag Group. You can associate Tags to a Tag Group in "Administration / Custom Fields".
More information on how to manage tagging you find here.