Next prev throug same category for post and portfolio

fucntions.php

function presscore_new_post_navigation( $args = array() ) {
		if ( ! in_the_loop() ) {
			return '';
		}

		$defaults = array(
			'prev_src_text'          => __( 'Previous post:', 'the7mk2' ),
			'next_src_text'          => __( 'Next post:', 'the7mk2' ),
			'in_same_term'       => false,
			'excluded_terms'     => '',
			'taxonomy'           => 'category',
			'screen_reader_text' => __( 'Post navigation', 'the7mk2' ),
		);
		$args = wp_parse_args( $args, $defaults );

		$config = presscore_config();
		$output = '';

		if ( $config->get( 'post.navigation.arrows.enabled' ) ) {
			$prev_text = '<i class="icomoon-the7-font-the7-arrow-29-3" aria-hidden="true"></i>' .
			             '<span class="meta-nav" aria-hidden="true">' . __( 'Previous', 'the7mk2' ) . '</span>' .
			             '<span class="screen-reader-text">' . esc_html( $args['prev_src_text'] ) . '</span>' .
			             '<span class="post-title h4-size">%title</span>';

			// We use opposite order.
			if ( 'post' == get_post_type() ) {
				$prev_link = get_previous_post_link(
				'%link',
				$prev_text,
				true,
				$args['excluded_terms'],
				$args['taxonomy']
				);
			}             
			elseif ( 'dt_portfolio' == get_post_type() ) {
				$prev_link = get_previous_post_link(
				'%link',
				$prev_text,
				true,
				$args['excluded_terms'],
				'dt_portfolio_category'
				);
			}

			else { 
				$prev_link = get_previous_post_link(
					'%link',
					$prev_text,
					$args['in_same_term'],
					$args['excluded_terms'],
					$args['taxonomy']
				);
			}
			$prev_link = str_replace( '<a', '<a class="nav-previous"', $prev_link );

			if ( ! $prev_link ) {
				$prev_link = '<span class="nav-previous disabled"></span>';
			}

			$output .= $prev_link;
		}

		if ( $config->get( 'post.navigation.back_button.enabled' ) ) {
			$output .= presscore_get_post_back_link( '<i class="dt-icon-the7-misc-006-1" aria-hidden="true"></i>' );
		}

		if ( $config->get( 'post.navigation.arrows.enabled' ) ) {
			$next_text = '<i class="icomoon-the7-font-the7-arrow-29-2" aria-hidden="true"></i>' .
			             '<span class="meta-nav" aria-hidden="true">' . __( 'Next', 'the7mk2' ) . '</span>' .
			             '<span class="screen-reader-text">' . esc_html( $args['next_src_text'] ) . '</span>' .
			             '<span class="post-title h4-size">%title</span>';

			// We use opposite order.
			if ( 'post' == get_post_type() ) {
				$next_link = get_next_post_link(
				'%link',
				$next_text,
				true,
				$args['excluded_terms'],
				$args['taxonomy']
				);
			}             
			elseif ( 'dt_portfolio' == get_post_type() ) {
				$next_link = get_next_post_link(
				'%link',
				$next_text,
				true,
				$args['excluded_terms'],
				'dt_portfolio_category'
				);
			}

			else { 
				$next_link = get_next_post_link(
					'%link',
					$next_text,
					$args['in_same_term'],
					$args['excluded_terms'],
					$args['taxonomy']
				);
			}
			$next_link = str_replace( '<a', '<a class="nav-next"', $next_link );

			if ( ! $next_link ) {
				$next_link = '<span class="nav-next disabled"></span>';
			}

			$output .= $next_link;
		}

		if ( $output ) {
			$output = '<nav class="navigation post-navigation" role="navigation"><h2 class="screen-reader-text">' . esc_html( $args['screen_reader_text'] ) . '</h2><div class="nav-links">' . $output . '</div></nav>';
		}

		return $output;
}

Try this code in your child theme functions.php to navigate to Portfolio Next Prev button only through same category.