Model/Adminhtml/Source/Customer/Attributes/Select.php
public function toOptionArray()
    {
        $options = [];
        //exclude attributes from mapping
        $excluded = [
            'created_at',
            'created_in',
            'dob',
            'dotmailer_contact_id',
            'email',
            'firstname',
            'lastname',
            'gender',
            'group_id',
            'password_hash',
            'prefix',
            'rp_token',
            'rp_token_create_at',
            'website_id',
        ];
        $attributes = $this->customerFactory->create()
            ->getAttributes();

        foreach ($attributes as $attribute) {
            if ($attribute->getFrontendLabel()) {
                $code = $attribute->getAttributeCode();
                //escape the label in case of quotes
                $label = $this->escaper->escapeQuote($attribute->getFrontendLabel());
                if (!in_array($code, $excluded)) {
                    $options[] = [
                        'value' => $attribute->getAttributeCode(),
                        'label' => $label,
                    ];
                }
            }
        }

        return $options;
    }
public function toOptionArray()
    {
        $options = [];
        //exclude attributes from mapping
        $excluded = [
            'created_at',
            'created_in',
            'dob',
            'dotmailer_contact_id',
            'email',
            'firstname',
            'lastname',
            'gender',
            'group_id',
            'password_hash',
            'prefix',
            'rp_token',
            'rp_token_create_at',
            'website_id',
        ];
        $attributes = $this->customerFactory->create()
            ->getAttributes();

        foreach ($attributes as $attribute) {
            if ($attribute->getFrontendLabel()) {
                $code = $attribute->getAttributeCode();
                //escape the label in case of quotes
                $label = $this->escaper->escapeQuote($attribute->getFrontendLabel());
                if (!in_array($code, $excluded)) {
                    $options[] = [
                        'value' => $attribute->getAttributeCode(),
                        'label' => $label,
                    ];
                }
            }
        }

        return $options;
    }
public function toOptionArray ( ) { $ options = [ ] ; //exclude attributes from mapping $ excluded = [ 'created_at' , 'created_in' , 'dob' , 'dotmailer_contact_id' , 'email' , 'firstname' , 'lastname' , 'gender' , 'group_id' , 'password_hash' , 'prefix' , 'rp_token' , 'rp_token_create_at' , 'website_id' , ] ; $ attributes = $ this -> customerFactory -> create ( ) -> getAttributes ( ) ; foreach ( $ attributes as $ attribute ) { if ( $ attribute -> getFrontendLabel ( ) ) { $ code = $ attribute -> getAttributeCode ( ) ; //escape the label in case of quotes $ label = $ this -> escaper -> escapeQuote ( $ attribute -> getFrontendLabel ( ) ) ; if ( ! in_array ( $ code , $ excluded ) ) { $ options [ ] = [ 'value' => $ attribute -> getAttributeCode ( ) , 'label' => $ label , ] ; } } } return $ options ; }
Customer custom attributes.

@return array
Customer custom attributes .