The partial search :
It only works on the filter "Formula"
There are 2 characters that you can use :
'*' → replace a digit (between 0 and 9) - Example : H* will return H1, H2, H3 ... H9
'_' → replace all characters - Example : C_Cl_ will return all molecules that contain C and Cl : CH2Cl2, CHBrClF...