Nanoconfined alkali metal borohydrides are promising materials for reversible hydrogen storage applications, but the characterization of hydrogen sorption in these materials is difficult. Here we show that with in-situ x-ray Raman spectroscopy (XRS) we can track the relative amounts of intermediates and final products formed during de- and re-hydrogenation of nanoconfined lithium borohydride (LiBH4) and therefore we can possibly identify the de- and re-hydrogenation pathways. In the XRS of nanoconfined LiBH4 at different points in the de- and re-hydrogenation, we identified phases that lead to the conclusion that de- and re-hydrogenation pathways in nanoconfined LiBH4 are different from bulk LiBH4: Intercalated lithium (LiCx), boron and lithium hydride were formed during de-hydrogenation, but as well Li2B12H12 was observed indicating that there is possibly some bulk LiBH4 present in the nanoconfined sample LiBH4/C as prepared. Surprisingly, XRS revealed that the de-hydrogenated products of the LiBH4/C nanocomposites can be partially rehydrogenated to about 90% of Li2B12H12 and 2-5% of LiBH4 at a mild condition of 1 bar H2 and 350oC. This suggests that re-hydrogenation occurs via the formation of Li2B12H12. Our results show that XRS is an elegant technique that can be used for in- and ex-situ study of the hydrogen sorption properties of nanoconfined and bulk light-weight metal hydrides in energy storage applications.