# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(\([^()]*\)[[:blank:]][[:blank:]]*)[^()]*\([^()]*\.([^()]*)\)/$1$2/gm;t' <<< "TREE(abc/x73/APPLE) DEST(MYFILE.FILE1A)
TREE(abc/x74/APPLE) DEST(MYFILE88.FILE1A)
TREE(abc/x100/APPLE) DEST(MYFILE100.FILE1B)
TREE(abc/x61/APPLE) DEST(MYFILE1000.FILE1A)"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html