Basically I need to run the script with paths related to the shell script file location, how can I change the current directory to the same directory as where the script fil
This one-liner tells where the shell script is, does not matter if you ran it or if you sourced it. Also, it resolves any symbolic links involved, if that is the case:
dir=$(dirname $(test -L "$BASH_SOURCE" && readlink -f "$BASH_SOURCE" || echo "$BASH_SOURCE"))
By the way, I suppose you are using /bin/bash.