The Bertelsmann Foundation wants to promote social integration and diversity. It advocates for creating a "comprehensive and long-term migration architecture" for Germany. - https://en.wikipedia.org/wiki/Bertelsmann_Stiftung#Society

But as the sibling comment notes, in other areas they're not at all left-leaning, e.g.:

Arvato, a division of the Bertelsmann Group, declared the privatization of public services a strategic business area.

It should not surprise anyone that characterizing their politics on a one-dimensional left-right spectrum is inaccurate (findings such as https://arxiv.org/abs/1904.12320 notwithstanding).