Is there a way to merge multiple variable valuses into one?

I am doing emmeans analysis for my bachelors thesis. I am analysing households incomes based on different variables like education, number of children, job sector, area ect.

The question is: Is there a way to merge eg. multiple living areas into one, as they have basically the same mmean and then construct the GLM again?

In SAS I would use this code to merge 3 areas into one: ESTIMATE "BB-KE-ZA" intercept 3 REGION 1 1 0 0 0 0 1 /divisor=3;

and I wish to do the same in R.

I wish to create new value of the variable Region where will be merged 3 values of the variable Region that have same least square means.

See the FAQ: How to do a minimal reproducible example reprex for beginners for a way to clearly illustrate the problem. It's unclear which variables, how they are coded and what object (data frame, matrix, S4 object, etc.?)