In Digambar Jain tradition, after Acharya Shri Vidyasagar Ji Maharaj’s samadhi in February 2024, his declared successor (uttaradhikari) is his disciple:

Acharya Shri Samaysagar Ji Maharaj (earlier known as Muni Samaysagar Ji before being made Acharya)

He is the Acharya of that same Vidyasagar Ji lineage of Digambar munis. Jain Dharma does not have one single “head” for all Jains; different sanghs and lineages have their own Acharyas.

You can read a short note about Acharya Vidyasagar Ji and this succession here