Idea: Provide filter dropdown in entity selector

[marcelgerber]

Core problem

It is currently hard to discover the different kinds of entities available in a chart.
For example, it is unclear at first sight that "special" entites and groupings like "Africa", "World", "Upper-middle income countries" are all part of the entity selector.

We have some of this information readily available in https://github.com/owid/owid-grapher/blob/104ca296e72a8222d184618c6f0d2eb3aba98376/packages/%40ourworldindata/utils/src/regions.json (although this information is arguably imperfect, as it doesn't include all historical countries, or groupings like Africa (FAO) - but we can strive to improve on that front!).

Proposed solution

One option would be to provide a dropdown in the entity selector, where the user can filter for the entity types they want to see, e.g.

Group name	Example
Countries	Zimbabwe
Historical countries & regions	Austria-Hungary
Continents	Asia
Income groups	Low-income countries
Regions & groupings [other than continents & income groups]	Americas (FAO), Asia (excl. China & India), European Union (27), World
Others	International aviation, Eggs, BloombergGPT

Multi-select would probably be allowed in that dropdown.

Additional context

This dropdown could also be very handy on the table tab, providing a similar filtering function.
And it could replace the current split into "Country/area" and "Other", thereby solving #3335.

Mockup

[danyx23]

This makes sense but we are a bit unsure if the drop down makes the entity selector too busy. Another approach that could also be considered is to turn the list of checkboxes under countries and regions into a list of notion style toggle triangle headings (i.e. one for Income groups, Continents etc) with the items inside it.

We think it would be good to discuss this with @mrwbkrm (maybe at the next data viz triage meeting)

[mrwbkrm]

Hey there! Yes, I did some discovery work on this back in the day! Here you can find some outdated sketches with some ideas there.
Open to discussing whenever you like!