#!/bin/bash
result=("school/proj_1/file1.txt" "school/proj_1/file2.txt" "school/proj_1/file3.txt")
rx='school/proj_1/(.*)'
for i in "${result[@]}"; do
    echo "${i##*/}"
    if [[ "$i" =~ $rx ]]; then
    	echo "${BASH_REMATCH[1]}"
    fi
done