Oh sure. You must assign the table name to the project name, i.e. Project name: dataset.table Here is an example of my joining one of my tables against a table in a publicdata project:
select sum(a.is_male) from (select is_male, year from [publicdata:samples.natality]) a inner join (select year from [moshap.my_years]) b on a.year = b.year
source share