I have a small problem, I am looking for a way to use the search engine from Samsung one ui. I have searched in different options, and unfortunately I have not found anything. Please help me very nicely 
I don’t think Samsung provide access to their functions via shortcut or activity. You might as well use a different launcher, like Nova, that offers access to their search function.
I have been using Nova for a long time, and until now I used its search engine, but after changing to Samsung that one suits me better. However, maybe someone knows the solution, if not I am left to go back to Nova 
I understand. You can look for 3rd party solution like Tasker if you want to stick with OneUI.