Answered Input and Output Filters (Output Modifiers)

Output modifiers aren't able to handle that kind of multiple conditional. You'll need a custom snippet.

It is possible as far as I know (in Evo this worked):

[[*services-in-room:isnot=``:and:if=`[[*services-in-bathroom]]`:isnot=``:and:if=`[[*the-price-includes]]:isnot=``:then=`<a class="rooms-services">conteng</a>`]]

notempty is not a conditional modifier and you have to call the other TVs with if=`[[*tvname]]`

@Bob: Much faster is (almost) ignorable since it is used direct in the template and not in an iterated getResources chunk. And it is cacheable as far as I know.

@Nort: There was an missing ` in the modifier chain:

[[*services-in-room:isnot=``:and:if=`[[*services-in-bathroom]]`:isnot=``:and:if=`[[*the-price-includes]]`:isnot=``:then=`<a class="rooms-services">conteng</a>`]]

Thats the true reason to avoid such long output filter chains. Nested conditionals could cause problems too and should be avoided.

A custom snippet will be much faster (untested):

[[!CheckServices]]

/* CheckServices snippet */
$tvNames = array(
    'services-in-room',
    'services-in-bathroom',
    'the-price-includes'
);

foreach($tvNames as $name) {
    if (empty($modx->resource->getTVValue($name))) {
        return '';
    }
}

return '<a class="rooms-services">conteng</a>';