You right-click on the root, select repo-browser, find the relevant bits you want to download to your working copy, right click and select the “update to revision”.
To remove items you have downloaded, right click on the item in your working copy, select the same menu (update to revision) and select “exclude” from the depth box.
That’s the method I used with a very large repository. Only the bits I needed were checked out, when I needed them.