Search paging failed to switch pages

$_POST is for forms with <form method="POST"> , to use page you will probably have to use GET, assuming the url looks like this:

 pagina.php?busca=1

In all GET or POST variables always check the values for example:

$busca = '';
if (false === empty($_GET['busca']) && is_numeric($_GET['busca'])) {
    $busca = $_GET['busca'];
}

The empty checks whether the variable exists and whether it is empty.

Looking at the code you sent me I noticed that you tried to recreate the url, but in these querystring paging issues you can omit the url, in this way for example:

<a href="?buscador=...&amp;pag=1">1</a>

The form should look like this:

<form class="pesquisa" action="pesquisa.php" method="GET">
    <input type="search" name="busca" class="input-busca" placeholder="Faça uma pesquisa.."  required>
</form>

  

Note: type=search may not be supported by all browsers.

The pagination should look like this:

<div class="paginacao">
<?php
$busca = '';
if (false === empty($_GET['busca']) && is_numeric($_GET['busca'])) {
    $busca = htmlspecialchars($_GET['busca']);
}

$buscaQueryString = '?buscador=' . $busca . '&amp;pag=';//Gera a querystring da páginação

if($pag != 1){
    echo '<a href="', $buscaQueryString, $pag - 1,'">Anterior</a>'; 
}
if($contador<=$maximo){
    echo "<td>Existe apenas uma única página</td>";
} else{
    for($i=1;$i<=$paginas;$i++){
        if($pag==$i){
            echo '<a class="link-ativo" href="', $buscaQueryString, $i,'">', $i, '</a>';
        } else {
            echo '<a href="', $buscaQueryString, $i,'">', $i, '</a>';
        }
    }
}
if($pag != $paginas){
    echo '<a href="', $buscaQueryString, $pag + 1,'">Anterior</a>'; 
}
?>
</div>

And the other file like this:

<?php
include('../../config.php');

$busca = '';
if (false === empty($_GET['busca']) && is_numeric($_GET['busca'])) {
    $busca = htmlspecialchars($_GET['busca']);
}

include('../header.php');

$sql_res=mysqli_query($conexao,"SELECT * FROM conteudo WHERE MATCH (titulo, texto, autor, id_categoria, id_pontos, id_orixas) AGAINST ('$busca') ORDER BY id DESC");
$contador=mysqli_num_rows($sql_res);
//Verificando se já selecionada alguma página
if(empty($_GET['pag'])) {
    $pag=1;
}else{
    $pag = $_GET['pag'];
} //Pegando página selecionada na URL

if($pag >= 1){
        $pag = $pag;
}else{
    $pag = '1';
}
$maximo=2; //Quantidade Máxima de posts por página
$inicio = ($pag * $maximo) - $maximo; //Variável para LIMIT da sql
$paginas=ceil($contador/$maximo);   //Quantidade de páginas 

$sql = "SELECT * FROM conteudo WHERE MATCH (titulo, texto, autor, id_categoria, id_pontos, id_orixas) AGAINST ('$busca') ORDER BY id DESC LIMIT $inicio, $maximo";
$exe = mysqli_query($conexao, $sql);
$contaRegistros = mysqli_num_rows($exe);
?>

Note that echo can work with commas instead of dots and I have inverted the apostrophes with the quotation marks because for the html it might be better to use quotation marks.

Read the documentation:

• link
• link

Are you putting the search field in a form? Try:

<form method="POST" action="buscar.php">
<input type="text" name="busca" placeholder="Digite aqui...">
<input type="submit" value="Buscar">
</form>

And in the fetch file, you should only have:

<?php
$busca = $_POST['busca']; 

seu código aqui

?>

If you show your code, it will be easier.