How can I match and redirect urls starting with something

About redirects...

[quote]Create a moved (HTTP 301) rule

Match: ^https?://([^/]*)/oldpage(\?|$)
Redirect: https://$1/newpage[/quote]
How can I create rule that will redirect all urls start with:

https://mydomain.com/kategorija-izdelka/
https://mydomain.com/izdelek/

For example:

https://mydomain.com/kategorija-izdelka/category-1
https://mydomain.com/kategorija-izdelka/category-2/subcategory

to:
https://mydomain.com/

Because I see in log that if url is not exactly https://mydomain.com/kategorija-izdelka, get redirected to https://mydomain.com/subcategory instead just to to https://mydomain.com.

Short answer:
^https://www\.mydomain\.com/kategorija-izdelka/.*
^ match string beginning
. matches an actual dot
. match any character

• continously

Some explainations:

To match urls starting with.
[b]^[/b]https://mydomain\.com/kategorija-izdelka/

To match both http and https, make s optional by succeeding it by a ?
^http[b]s?[/b]://mydomain.com/kategorija-izdelka/

To match both or without www., group it with a paranthesis and succeed it by a ? to make it optional:
^https?://b?[/b]mydomain.com/kategorija-izdelka/
(This group is captured and retrieved by $1 if you need it in your redirect url)

To match any domain, [^/] means anything that is not a slash / and means continously:
^https?://[b]([^/])[/b]/kategorija-izdelka/

To match an exact url, and nothing else preceeding or following.
[b]^[/b]https://mydomain\.com/kategorija-izdelka/[b]$[/b]

..and to make the last slash optional
^https://mydomain\.com/kategorija-izdelka[b]/?[/b]$

To match an exact url [u]with optional query parameters following[/u]. (\?|$) means match a question mark or the end of string.
[b]^[/b]https://mydomain\.com/kategorija-izdelka/?[b](\?|$)[/b]

Use this online tool for toying with regex:
https://regex101.com/

^https://mydomain\.com/kategorija-izdelka/ will turn https://mydomain\.com/kategorija-izdelka[b]/remainings[/b] into https://redirectdomain\.com[b]/remainings[/b].
While ^https://mydomain\.com/kategorija-izdelka/.*$ will turn https://mydomain\.com/kategorija-izdelka/remainings into https://redirectdomain\.com/.

@tim Thank you very much for detailed and easy explanation!