The latest version of the Tag Groups plugin fixes several bugs and adds two new shortcode parameters that help you fine-tune which tags to display in the tag cloud. As their names already suggest, include_terms lets you set a list of tags (terms) that alone should be included, while exclude_terms does the opposite – all mentioned tags will be excluded.((Don’t confuse it with include, which is about groups, not tags.))
This list needs to be formatted as a comma-separated (or space-separated, but then necessarily wrapped into quotes) list of tag IDs. One single ID can of course be written without a comma. Example:
[tag_groups_accordion collapsible=1 active=0 heightstyle=content exclude_terms="7,65,75" hide_empty_content=1]
If you don’t know how to find the IDs of tags (or other terms), here is a hint: Go to the menu Posts → Tags. Hover over a tag, or click on it. In the link you find a piece like “&tag_ID=” – the number behind it is the ID. If that is too cumbersome, you may want to install a plugin like Catch IDs that simply displays the IDs in a new column.