I am curious about in between sounds. I mean in between as in being made in different regions of the mouth. For example, [f] is between [ɸ] and [θ]. So, I want to know what sounds are between [x] and [h].
If you look at an IPA consonant chart, the places of articulation are listed from front to back.
/x/ is a velar sound, pronounced with the most relevant constriction at the velum;
/h/ is (generally treated as) a glottal sound, pronounced with the most relevant constriction at the glottis.
In between velar and glottal are two categories on the IPA chart, uvular and pharyngeal. The voiceless fricatives in these categories are written
/ħ/, and are used in languages like Tlingit and Arabic.