[tune] How to use grid search in TuneBOHB

I want to do grid search for some of the hyperparameters, while other hyperparameters are searched by TuneBOHB.
Then I got an error:
Grid search parameters cannot be automatically converted to a TuneBOHB search space.

Is there any customized way to solve this problem? Or is there any reason for which TuneBOHB cannot do grid search?

Thanks in advance!