You can do this by building a profiler.
There is some general guidance on building profilers here:
I suspect you will have to do this by defining the level of similarity to each of your 30 chemicals.
In addition I would recommend that you also define your similarity based on the profiling results which are common to all the members of the group.
You can then run your new profiler on any list of chemicals and find chemicals which potentially belong to your group.
Hope this helps
I don't think you can load a list of chemicals into your custom profiler.
You will have to define the similarity rules against each and every chemical in your group and then logically group them, e.g.
>50% similarity with chemical 1 from your group AND >50% similarity with chemical 2 from your group AND ...
But once again, as I mentioned above, it might make more sense not to build your profiler based on mathematical structural similarity, but according to the commonalities in structure in your group as well as the results from the other profilers, e.g.
Aromatic (according to organic functional groups) AND Schiff base former according to Protein binding by OASIS AND...