/usr/share/bedtools/test/closest/mdb2.bed is in bedtools-test 2.25.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3
chr1 15 35 db2.1 1 - chr1 120 170 db2.2 2 - chr1 210 230 db3 3 +