Please refer to following links for filename in a tar archive with ustar format:
https://www.ibm.com/docs/en/aix/7.1?topic=files-tarh-file
"The file's path name is created using this field, or by using this field in connection with the prefix field. If the prefix field is included, the name of the file is prefix/name. This field is null-terminated unless every character is non-null."
Please refer to following links for filename in a tar archive with ustar format:
https://www.ibm.com/docs/en/aix/7.1?topic=files-tarh-file "The file's path name is created using this field, or by using this field in connection with the prefix field. If the prefix field is included, the name of the file is prefix/name. This field is null-terminated unless every character is non-null."
https://en.wikipedia.org/wiki/Tar_(computing)#UStar_format "The maximum filename size is 256, but it is split among a preceding path "filename prefix" and the filename itself "
https://www.gnu.org/software/tar/manual/html_chapter/Formats.html#Compression "File names longer than 100 bytes must be split at a directory separator in two parts, the first being at most 155 bytes long. So, in most cases file names must be a bit shorter than 255 bytes."