How can we separate two immiscible liquids which have same boiling point?
It’s very unlikely two materials will have both the same boiling AND melting point. Hence you can try cooling down and let one of the two liquids precipitate. Then filter the liquid and so it again until it’s pure.
However a more sophisticated method is Chromatography and HPLC (High-performance liquid chromatography). For this you need a Chromatograph or a HPLC machine, and the right columns, of course