Regex to fetch string after character and before word

I’m trying to code a regex to fetch a portion of a string that is between a character and a word.

E.g.

FIRST/SECOND/999999/MATCH EVERYTHING HERE BEFORE third

It should fetch the word between "999999/" (this section will always be numeric, 6 digit, and end with a forward slash) and "third" (this word does not change).
Expected result: MATCH EVERYTHING HERE BEFORE

I ended up with the following Regex, but it only fetches the word if there’s a whitespace before the word ‘MATCH’:

/(?<=/\s).*(?=\sthird)/

Can anyone help?

Thanks!

Edit: updated for clarification. Thanks @JvdV

>Solution :

It looks like the following should work:

(?:^|\/)\d{6}\/([^\/]+?)\s*\bthird

See an online demo

• (?:^|\/) – Non-capture group for start-line anchor or forward slash;
• \/ – A literal forward slash;
• ([^\/]+?) – Capture group to catch 1+ (lazy) characters other than forward slash;
• \s*\bthird – 0+ Whitespace characters, a word-boundary and literally the word third.