The local electrical conductivity and impurity band evolution in superconducting nanocrystalline boron doped diamond (BNCD) film are investigated using conducing atomic force microscopy (C-AFM) and X-ray absorption spectroscopy (XAS). C-AFM has been employed to investigate the local conductivity of superconducting BNCD with T-c = 4.3 K and upper critical field H-c2(0) = 5.2 T. A high local electrical heterogeneity of the BNCD film as evidenced from the C-AFM profile points to the uneven boron uptake during the process of doping. C-AFM also revealed that grain boundaries are the highly conducing regions, possibly, due to the presence of p-type transpolyacetylene along with the C-C and C-H bonds in the grain boundaries. From the in-depth XPS profiling of the B 1s spectra we confirmed the macroscopic uniformity of the boron concentration across the depth of BNCD layers. X-ray absorption spectroscopy (XAS) measurements near B K-edge and C K-edge showed formation of in - gap states as a result of heavy boron doping. Near C K-edge, bandgap states at 282.8 eV and 284.1 eV are found which are responsible for superconductivity in the BNCD film. This work explores the non-uniform boron doping and its effect on the conduction band structure of a superconducting BNCD film.