Is there a way to get the timeseries of BHE In- and Outlet Temperatures similar to doc.c.hist.df.HEAD?

It would already help to see which histories are available.
In the ifm_contrib documentation it states that "Calling the hist function without arguments returns a dictionary of all available histories".
I am already failing to get that dictionary.

In the end I want to calculate the efficiency of a Borehole Thermal Energy Storage.

Any help would be appreciated.