The OECD's Functional urban areas by country has shapefiles of urban areas by country with the population living within those areas. They have data for France, Belgium, and Germany. The population data appears to be from 2015. They have summary reports for each country and use 4 sub-classes of urban areas.
Here is the link:http://www.oecd.org/cfe/regional-policy/functionalurbanareasbycountry.htm