Try this code:
var pattern = /<tag.*?>(.*?)<\/tag.*?>/g; //Padrão que a regex vai dar Match
var reader = new FileReader(); //Leitor do arquivo txt
var output = ""; //Variável de texto onde será carregado o conteúdo do txt
reader.onload = function (e) {  //Função para leitura após o carregamento do reader
            output = e.target.result;
            displayContents(output);
        }; //Fim da função
        reader.readAsText(filePath.files[0]); //insira o path para seu txt
var m;
do {
    m = pattern.exec(output); //executa o padrão da regex e armazena os val em m
    if (m) {
        console.log(m[1]); //mostra o resultado no console do browser
    }
} while (m); 
Explanation of the code:
The following function loads the txt file through a FileReader
 
Passes your content to the variable output.
 
Print the content that match regex in the browser console.
 
Explanation of the regex:
/<tag.*?>(.*?)<\/tag.*?>/g;
<tag Finds the sequence exactly equal to <tag 
.*?> Continues (without capturing) by all characters until the first occurrence of >. 
(.*?)<\/tag Captures all content in capture group 1 until the first occurrence of </tag 
.*?> Continues (without capturing) by all characters until the first occurrence of >. 
/g It is a regex modifier, indicates that you should continue trying to match until the end of the text sequence. 
							
							
						 
You want to take the text between the <tag1> and <tag2> tags, is that it? If it’s no problem to put the application code, it would be easier to help...
– Lucas Souza
That’s it! My system needs to do this with this txt.
– use777
I don’t understand if you want to capture
tituloandsubtituloor what is outside the tags astexto....– Sergio
and why the
<tag2>is not closed?– Mariano
I want to take what’s outside the tags.
– use777
forgot to close.
– use777