HideFields.php

<?php

Craft::$app->getView()->hook(
/**
 * @param array $context
 */
    'cp.entries.edit',
    function(array &$context) {
        /** @var Section $section */
        $section = $context['section'];

        /** @var \craft\models\EntryType $entryType */
        $entryType = $context['entryType'];

        /** @var Entry $entry */
        $entry = $context['entry'];
        /**
         * Array of field handles you want to remove
         */
        $fieldsYouWantToRemove = [
            'relation',
            'tag',
            'category'
        ];

        // include certain conditions you like, either by registering custom permissions and do
        // Craft::$app->getUser()->checkPermission('myFancyPermission');
        // or just search for the current users groups
        // Craft::$app->getUser()->getIdentity()->getGroups();
        if($entry->siteId === 4 && $section->handle === 'insertYourSectionHandle' && $entryType->handle === 'yourEntryTypeHandle'){
            // grab all the fields in the layout
            foreach ($entryType->getFieldLayout()->getTabs() as $tab){
                /** @var \craft\base\Field[] $fields */
                $fields = $tab->getFields();
                foreach ($fields as $key => $field){
                    // check if the fields handle is forbidden
                    if(in_array($field->handle, $fieldsYouWantToRemove, true) === true){
                        // remove the field
                        unset($fields[$key]);
                    }
                }
                // set the fields back
                $tab->setFields($fields);
            }    
        }
    }
);

?>