/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.*;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String rx = "(?sm)(\\G(?!\\A)|^sufixpart$)(?:(?!^(?:sufixpart|end)$).)*?(subdata\\S*)(?=.*?^end$)";
		String s = "invalidsufix\nsubadatax\nsufixpart\nsubdata1\nsomerandomn\nsubdata2\nsubdatan\nend\ninvalidsufix\nsubadatax\nsufixpart\nsubdata001\nsomerandomn\nsubdata002\nsubdata00n\nend";
		Pattern pattern = Pattern.compile(rx);
		Matcher matcher = pattern.matcher(s);
		List<List<String>> res = new ArrayList<>();
		List<String> lst = null;
		while (matcher.find()){
			if (!matcher.group(1).isEmpty()) {
				if (lst != null) res.add(lst);
				lst = new ArrayList<>();
				lst.add(matcher.group(2));
			} else lst.add(matcher.group(2)); 
		} 
		if (lst != null) res.add(lst);
		System.out.println(res); 
	}
}

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