^start of line
Positive Lookahead(?=[^/]*\btop\s) Negated Character Class[^/]* *matches any number of characters outside the set below:
/the literal / (4710 / 578 / 2F16)
\ba Unicode word boundary
topthe literal text top (case sensitive) \sa Unicode whitespace character
Negated Character Class[^/]* *matches any number of characters outside the set below:
/the literal / (4710 / 578 / 2F16)
radiothe literal text radio (case sensitive) Negated Character Class[^/]+ +matches at least one character outside the set below:
/the literal / (4710 / 578 / 2F16)
\d{2}a Unicode decimal digit, repeated exactly 2 times
\s+a Unicode whitespace character, repeated at least once
/the literal / (4710 / 578 / 2F16)
\D*any character that is not a Unicode decimal digit, repeated any number of times
bottomthe literal text bottom (case sensitive) \s+a Unicode whitespace character, repeated at least once
\d{2}a Unicode decimal digit, repeated exactly 2 times
$end of line
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string