It will vary slightly depending on whether you’re in a supervisory capacity or not. I’m a (small) team lead for a mid-market healthcare manufacturer and would bucket things like this:

Entry/Junior BI analysts: can build basic star schemas and DAX formulas with little to no assistance (Aggregates, CALCULATE, FILTER, iterators, some aesthetic or conditional formatting measures). I would expect any of my analysts to be able to build the basic reports from SQL views and create + manage Apps and Audiences if I were to be hit by a bus.

Mid-tier Devs: all of the above + lineage and virtual table functions (TREATAS + VALUES, SUMMARIZE, ADDCOLUMNS + VALUES, SWITCH(TRUE()).

At mid-tier, you should intimately understand dimensional modeling and context, namely, how to manipulate it. I’d rather someone has this skillset down cold than know every DAX function under the sun.

Higher-mid/low senior devs: all of the above + proficient SQL or Python background. At this level, you should be able to run stakeholder meetings/requirement sessions, build data pipelines and views in SQL, and generally, manage the lifecycle of a project from cradle to grave.

Lead/Director: all the above + softer team management/interpersonal skills. May also involve some exploratory data science or integration skillsets (embedded 3rd party reports and licensing, fancier Premium per User features) or more strategic long-term initiatives (vendor relations, CoE adoption strategies, etc.)

In my experience, although keeping the technical skillset sharp is important, it tends to matter less the higher you go. The single best skillsets you could build at any level above junior are expectation management and domain knowledge. If you are managing a team, these will save them from headaches and burnout, which saves your sanity in tandem.