Its a grouping of 5 smaller leftish parties, so pretty ideologically diverse. It only came together like two months ago per CNN, ad hoc when Macron called for the general election.

Their main unifying factor is not wanting the far right in control.

Center left neoliberals (your modern socdems) are the second largest party in the coalition, the first are left populists based around the celebrity character of Melenchon, the 3rd are green eurocucks and 4th are the old school communists, then there's a sputtering of center to left parties