I have CSV file with breadcrumb (prestastop products)

I want to delete the content after last separator (product name), my structure is:

col1|col2|col3|product

I can delete with simple regex, problem is that number of separators is not always the same so for example `([^|]+/[^|]+/[^|]+/[^|]+|).*` wont work.

Is there any way to do it with one regex?

I want:

```
col1|col2|col3|product
col1|col2|col3|col4|product
col1|col2|col3|col5|product

```

to become 

```
col1|col2|col3
col1|col2|col3|col4
col1|col2|col3|col5

```

I think the simple way would be to read from right to left and not left to right...