const string = "(https://test.blob.core.windows.net/raw/DET_IM_3TM5_]Systems_Manual.pdf?st=2024-03-08T17:02:24Z&se=2138-04-07T09:02:24Z&sp=r&spr=https&sv=2023-11-03&sr=b&sig=MRCMS0OCPSBc1NhAjIPE%3D) - [491](https://test.blob.core.windows.net/raw/DET_IM_3TM5_Manual.pdf?st=2024-03-08T17:02:24Z&de=2138-04-07T09:02:24Z&sp=r&spr=https&sv=2023-11-03&sr=b&sig=MRXa1O9AxHW8IPE%3D#page=491)(https://sa003stdirtest.blob.core.windows.net/raw/DET_IM_3TM5_]Systems_Manual.pdf?st=2024-03-08T17:02:24Z&se=2138-04-07T09:02:24Z&sp=r&spr=https&sv=2023-11-03&sr=b&sig=MRCMS0OCcIPE%3D) - [492](https://ditest.blob.core.windows.net/raw/DET_IM_3TM5.pdf?st=2024-03-08T17:02:24Z&se=2138-04-07T09:02:24Z&sp=r&spr=https&sv=2023-11-03&sr=b&sig=MRCMS0OCD#page=492)";


const regex = /(?:https?|ftp):\/\/[\n\S]+?(?=\s|$|\)|\()|www\.[\n\S]+?(?=\s|$|\)|\()|\[\d+\]\((.*?)\)/gi;

// Array to store matched URLs
const urls = [];

// Match URLs and push them to the array
let match;
while ((match = regex.exec(string)) !== null) {
  // Extract only the URLs contained within [number](url) pattern
  if (match[1]) {
    urls.push(match[1]);
  }
}
console.log(urls);

Replace string variable by your string attribute.

You can use above code in javascript action.

Hope this will work.

This case can use java action to split it into a entity list. for example URL entity list then the input to java action should be String . After found the url in string add to the list and then commit. 

Code: 

import java.util.regex.Matcher;
import java.util.regex.Pattern;

//Begin
    IContext context = this.getContext();
    String inputText = this.InputText; // Assume InputText is the parameter name for input text

    // Regex to find URLs
    Pattern pattern = Pattern.compile("https:\\/\\/[^\s]+");
    Matcher matcher = pattern.matcher(inputText);

    while (matcher.find()) {
        String foundUrl = matcher.group();

        // Create new URL object and set its attribute
        URL urlObject = new URL(context);
        urlObject.setUrlString(foundUrl);
        Core.commit(context, urlObject);
    }

    return null;
//End

Hey!

Substring and find functions should also work

something like find($string,'https',1) --> meaning first occurance

then store this number in a variable

find ($string,')') store in another variable 

and substring($string,$var1,$var2) should work

Here is a way to do this using Mendix capabilities only

Running this microflow displays the following in the Console: