How to filter runs using multiple flag values

Hi,

I would like to know if there is a way to filter runs using multiple flag values.

For example I have a batch of runs with flags: a=1/2/3, b=4/5/6 (so in total 9 runs). And I would like to filter the runs using

guild runs -Fl a=1 -Fl b=4

I expect it return runs with a=1 AND b=4
But seems the command would return runs with a=1 OR b=4?

So how can I get runs with a=1 AND b=4? Thanks!