This bit from Ableton's Learn Live series covers how to find sounds quickly in Live 12's browser using its filter, tagging, search, and history tools. The focus is on the Sounds category, but the same system applies across the browser.
Filters are organized into tag groups, and you can select multiple tags within a group by holding Command (Mac) or Control (PC) to narrow results by combining criteria. Filters you use often can be pinned to the sidebar as custom labels, keeping your most useful combinations a single click away.
Beyond the built-in tags that come pre-applied to Live's library content, the Tag Editor lets you add your own tags to any item or create entirely new tag groups. This is where the system starts working for your specific workflow, letting you organize sounds in ways that reflect how you actually think about your sessions.
The search bar filters the current category by keyword, and you can prefix any term with a hash symbol to search specifically by tag. Browser history lets you step backward and forward through past searches and filter states, so revisiting a useful combination doesn't mean rebuilding it from scratch.