Hello,
I created my own post’s taxonomy “date training” because one post has many date’s. My question is it is possible to use “date filter” to search for training but “data filet” gets a date from my tag “date training”?
Unfortunately that is not possible, as taxonomy terms are stored by IDs, and not by values. For the date filter to work, it needs a custom field value, with a properly stored MySQL datetime field.
Maybe ACF plugin can do that kind of data import, I am not sure.