I know it is old post, but people who are looking for answers like me below is what worked for me.

Option 1 (it is crude) but it works. We can also add regex '*' to include list of folders region=*. If you need to satisfy multiple conditions add them as comma separated.

DataFrame df = sparkSession.read()
.option("mergeSchema", true)
.option("basePath", "s3://some-bucket/some-path/")
.parquet("s3://some-bucket/some-path/region=na/days=1/",s3://some-bucket/some-path/region=us-east/days=1*");