Each tab keeps its single entries and its groups on their own pages rather than mixing them into one list with a filter. The toggle at the top carries a count for each side, so you can see at a glance what you have of both.

The Vault does the same, which is why a group you publish appears alongside other groups rather than buried among individual entries.

Select the entries you want in your Library, then Create Group. The group takes a Name, an optional Description for what holds it together, and any Tags you want it findable by.

Select entries and use Add to Existing Group, then pick the group. If you have no groups yet the dialog says so and points you at Create Group instead.

Publishing a group makes the group browsable. It does not publish the entries inside it.

If you want those to be findable on their own as well, publish them separately. This is deliberate: it lets you share a curated party without every character in it also turning up in single-entry searches.